Spin-Up Sample Exam Problems Discussion

[GreenNGold]

For problem 19 in exam 5, why is 2 x 10^-2 used rather than 4 x 10^ -7?

I have seen two equations for inductance per phase, (2 x 10^-7) ln (GMD/GMR) and (4 x 10^-7) ln (GMD/GMR). Can anyone clarify when each should be used? Thank you.

 

[GreenNGold]

Is (2 x 10^-7) ln (GMD/GMR) used when per phase inductance is asked for? And (4 x 10^-7) ln (GMD/GMR) for total inductance?

 

[Electron]

Do some searching on 3 Phase Inductance vs Single Phase Inductance Calculations.